Django的Form主要具有一下几大功能:
- 生成HTML标签
- 验证用户数据(显示错误信息)
- HTML Form提交保留上次提交数据
- 初始化页面显示内容
一、小试牛刀
1、创建Form类
1 from django.forms import Form 2 from django.forms import widgets 3 from django.forms import fields 4 5 class MyForm(Form): 6 user = fields.CharField( 7 widget=widgets.TextInput(attrs={‘id‘: ‘i1‘, ‘class‘: ‘c1‘}) 8 ) 9 10 gender = fields.ChoiceField( 11 choices=((1, ‘男‘), (2, ‘女‘),), 12 initial=2, 13 widget=widgets.RadioSelect 14 ) 15 16 city = fields.CharField( 17 initial=2, 18 widget=widgets.Select(choices=((1,‘上海‘),(2,‘北京‘),)) 19 ) 20 21 pwd = fields.CharField( 22 widget=widgets.PasswordInput(attrs={‘class‘: ‘c1‘}, render_value=True) 23 )
2、View函数处理
1 from django.shortcuts import render, redirect 2 from .forms import MyForm 3 4 5 def index(request): 6 if request.method == "GET": 7 obj = MyForm() 8 return render(request, ‘index.html‘, {‘form‘: obj}) 9 elif request.method == "POST": 10 obj = MyForm(request.POST, request.FILES) 11 if obj.is_valid(): 12 values = obj.clean() 13 print(values) 14 else: 15 errors = obj.errors 16 print(errors) 17 return render(request, ‘index.html‘, {‘form‘: obj}) 18 else: 19 return redirect(‘http://www.google.com‘)
3、生成HTML
1 <form action="/" method="POST" enctype="multipart/form-data"> 2 <p>{{ form.user }} {{ form.user.errors }}</p> 3 <p>{{ form.gender }} {{ form.gender.errors }}</p> 4 <p>{{ form.city }} {{ form.city.errors }}</p> 5 <p>{{ form.pwd }} {{ form.pwd.errors }}</p> 6 <input type="submit"/> 7 </form>
1 <form method="POST" enctype="multipart/form-data"> 2 {% csrf_token %} 3 4 {{ form.xxoo.label }} 5 {{ form.xxoo.id_for_label }} 6 {{ form.xxoo.label_tag }} 7 {{ form.xxoo.errors }} 8 <p>{{ form.user }} {{ form.user.errors }}</p> 9 <input type="submit" /> 10 </form> 11 12 其他标签有
其他标签有
二、Form类
创建Form类时,主要涉及到 【字段】 和 【插件】,字段用于对用户请求数据的验证,插件用于自动生成HTML;
1、Django内置字段如下:
1 Field 2 required=True, 是否允许为空 3 widget=None, HTML插件 4 label=None, 用于生成Label标签或显示内容 5 initial=None, 初始值 6 help_text=‘‘, 帮助信息(在标签旁边显示) 7 error_messages=None, 错误信息 {‘required‘: ‘不能为空‘, ‘invalid‘: ‘格式错误‘} 8 show_hidden_initial=False, 是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直) 9 validators=[], 自定义验证规则 10 localize=False, 是否支持本地化 11 disabled=False, 是否可以编辑 12 label_suffix=None Label内容后缀 13 14 15 CharField(Field) 16 max_length=None, 最大长度 17 min_length=None, 最小长度 18 strip=True 是否移除用户输入空白 19 20 IntegerField(Field) 21 max_value=None, 最大值 22 min_value=None, 最小值 23 24 FloatField(IntegerField) 25 ... 26 27 DecimalField(IntegerField) 28 max_value=None, 最大值 29 min_value=None, 最小值 30 max_digits=None, 总长度 31 decimal_places=None, 小数位长度 32 33 BaseTemporalField(Field) 34 input_formats=None 时间格式化 35 36 DateField(BaseTemporalField) 格式:2015-09-01 37 TimeField(BaseTemporalField) 格式:11:12 38 DateTimeField(BaseTemporalField)格式:2015-09-01 11:12 39 40 DurationField(Field) 时间间隔:%d %H:%M:%S.%f 41 ... 42 43 RegexField(CharField) 44 regex, 自定制正则表达式 45 max_length=None, 最大长度 46 min_length=None, 最小长度 47 error_message=None, 忽略,错误信息使用 error_messages={‘invalid‘: ‘...‘} 48 49 EmailField(CharField) 50 ... 51 52 FileField(Field) 53 allow_empty_file=False 是否允许空文件 54 55 ImageField(FileField) 56 ... 57 注:需要PIL模块,pip3 install Pillow 58 以上两个字典使用时,需要注意两点: 59 - form表单中 enctype="multipart/form-data" 60 - view函数中 obj = MyForm(request.POST, request.FILES) 61 62 URLField(Field) 63 ... 64 65 66 BooleanField(Field) 67 ... 68 69 NullBooleanField(BooleanField) 70 ... 71 72 ChoiceField(Field) 73 ... 74 choices=(), 选项,如:choices = ((0,‘上海‘),(1,‘北京‘),) 75 required=True, 是否必填 76 widget=None, 插件,默认select插件 77 label=None, Label内容 78 initial=None, 初始值 79 help_text=‘‘, 帮助提示 80 81 82 ModelChoiceField(ChoiceField) 83 ... django.forms.models.ModelChoiceField 84 queryset, # 查询数据库中的数据 85 empty_label="---------", # 默认空显示内容 86 to_field_name=None, # HTML中value的值对应的字段 87 limit_choices_to=None # ModelForm中对queryset二次筛选 88 89 ModelMultipleChoiceField(ModelChoiceField) 90 ... django.forms.models.ModelMultipleChoiceField 91 92 93 94 TypedChoiceField(ChoiceField) 95 coerce = lambda val: val 对选中的值进行一次转换 96 empty_value= ‘‘ 空值的默认值 97 98 MultipleChoiceField(ChoiceField) 99 ... 100 101 TypedMultipleChoiceField(MultipleChoiceField) 102 coerce = lambda val: val 对选中的每一个值进行一次转换 103 empty_value= ‘‘ 空值的默认值 104 105 ComboField(Field) 106 fields=() 使用多个验证,如下:即验证最大长度20,又验证邮箱格式 107 fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),]) 108 109 MultiValueField(Field) 110 PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用 111 112 SplitDateTimeField(MultiValueField) 113 input_date_formats=None, 格式列表:[‘%Y--%m--%d‘, ‘%m%d/%Y‘, ‘%m/%d/%y‘] 114 input_time_formats=None 格式列表:[‘%H:%M:%S‘, ‘%H:%M:%S.%f‘, ‘%H:%M‘] 115 116 FilePathField(ChoiceField) 文件选项,目录下文件显示在页面中 117 path, 文件夹路径 118 match=None, 正则匹配 119 recursive=False, 递归下面的文件夹 120 allow_files=True, 允许文件 121 allow_folders=False, 允许文件夹 122 required=True, 123 widget=None, 124 label=None, 125 initial=None, 126 help_text=‘‘ 127 128 GenericIPAddressField 129 protocol=‘both‘, both,ipv4,ipv6支持的IP格式 130 unpack_ipv4=False 解析ipv4地址,如果是::ffff:192.0.2.1时候,可解析为192.0.2.1, PS:protocol必须为both才能启用 131 132 SlugField(CharField) 数字,字母,下划线,减号(连字符) 133 ... 134 135 UUIDField(CharField) uuid类型 136 ...
注:UUID是根据MAC以及当前时间等创建的不重复的随机字符串
1 >>> import uuid 2 3 # make a UUID based on the host ID and current time 4 >>> uuid.uuid1() # doctest: +SKIP 5 UUID(‘a8098c1a-f86e-11da-bd1a-00112444be1e‘) 6 7 # make a UUID using an MD5 hash of a namespace UUID and a name 8 >>> uuid.uuid3(uuid.NAMESPACE_DNS, ‘python.org‘) 9 UUID(‘6fa459ea-ee8a-3ca4-894e-db77e160355e‘) 10 11 # make a random UUID 12 >>> uuid.uuid4() # doctest: +SKIP 13 UUID(‘16fd2706-8baf-433b-82eb-8c7fada847da‘) 14 15 # make a UUID using a SHA-1 hash of a namespace UUID and a name 16 >>> uuid.uuid5(uuid.NAMESPACE_DNS, ‘python.org‘) 17 UUID(‘886313e1-3b8a-5372-9b90-0c9aee199e5d‘) 18 19 # make a UUID from a string of hex digits (braces and hyphens ignored) 20 >>> x = uuid.UUID(‘{00010203-0405-0607-0809-0a0b0c0d0e0f}‘) 21 22 # convert a UUID to a string of hex digits in standard form 23 >>> str(x) 24 ‘00010203-0405-0607-0809-0a0b0c0d0e0f‘ 25 26 # get the raw 16 bytes of the UUID 27 >>> x.bytes 28 b‘\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f‘ 29 30 # make a UUID from a 16-byte string 31 >>> uuid.UUID(bytes=x.bytes) 32 UUID(‘00010203-0405-0607-0809-0a0b0c0d0e0f‘)
2、Django内置插件:
TextInput(Input) NumberInput(TextInput) EmailInput(TextInput) URLInput(TextInput) PasswordInput(TextInput) HiddenInput(TextInput) Textarea(Widget) DateInput(DateTimeBaseInput) DateTimeInput(DateTimeBaseInput) TimeInput(DateTimeBaseInput) CheckboxInput Select NullBooleanSelect SelectMultiple RadioSelect CheckboxSelectMultiple FileInput ClearableFileInput MultipleHiddenInput SplitDateTimeWidget SplitHiddenDateTimeWidget SelectDateWidget
三、常用选择插件
1 # 单radio,值为字符串 2 # user = fields.CharField( 3 # initial=2, 4 # widget=widgets.RadioSelect(choices=((1,‘上海‘),(2,‘北京‘),)) 5 # ) 6 7 # 单radio,值为字符串 8 # user = fields.ChoiceField( 9 # choices=((1, ‘上海‘), (2, ‘北京‘),), 10 # initial=2, 11 # widget=widgets.RadioSelect 12 # ) 13 14 # 单select,值为字符串 15 # user = fields.CharField( 16 # initial=2, 17 # widget=widgets.Select(choices=((1,‘上海‘),(2,‘北京‘),)) 18 # ) 19 20 # 单select,值为字符串 21 # user = fields.ChoiceField( 22 # choices=((1, ‘上海‘), (2, ‘北京‘),), 23 # initial=2, 24 # widget=widgets.Select 25 # ) 26 27 # 多选select,值为列表 28 # user = fields.MultipleChoiceField( 29 # choices=((1,‘上海‘),(2,‘北京‘),), 30 # initial=[1,], 31 # widget=widgets.SelectMultiple 32 # ) 33 34 35 # 单checkbox 36 # user = fields.CharField( 37 # widget=widgets.CheckboxInput() 38 # ) 39 40 41 # 多选checkbox,值为列表 42 # user = fields.MultipleChoiceField( 43 # initial=[2, ], 44 # choices=((1, ‘上海‘), (2, ‘北京‘),), 45 # widget=widgets.CheckboxSelectMultiple 46 # )
在使用选择标签时,需要注意choices的选项可以从数据库中获取,但是由于是静态字段 ***获取的值无法实时更新***,那么需要自定义构造方法从而达到此目的。
方式一:
1 from django.forms import Form 2 from django.forms import widgets 3 from django.forms import fields 4 from django.core.validators import RegexValidator 5 6 class MyForm(Form): 7 8 user = fields.ChoiceField( 9 # choices=((1, ‘上海‘), (2, ‘北京‘),), 10 initial=2, 11 widget=widgets.Select 12 ) 13 14 def __init__(self, *args, **kwargs): 15 super(MyForm,self).__init__(*args, **kwargs) 16 # self.fields[‘user‘].widget.choices = ((1, ‘上海‘), (2, ‘北京‘),) 17 # 或 18 self.fields[‘user‘].widget.choices = models.Classes.objects.all().value_list(‘id‘,‘caption‘)
方式二:
使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现
1 from django import forms 2 from django.forms import fields 3 from django.forms import widgets 4 from django.forms import models as form_model 5 from django.core.exceptions import ValidationError 6 from django.core.validators import RegexValidator 7 8 class FInfo(forms.Form): 9 authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all()) 10 # authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())
四、自定义验证规则
方式一:
1 from django.forms import Form 2 from django.forms import widgets 3 from django.forms import fields 4 from django.core.validators import RegexValidator 5 6 class MyForm(Form): 7 user = fields.CharField( 8 validators=[RegexValidator(r‘^[0-9]+$‘, ‘请输入数字‘), RegexValidator(r‘^159[0-9]+$‘, ‘数字必须以159开头‘)], 9 )
方式二:
1 import re 2 from django.forms import Form 3 from django.forms import widgets 4 from django.forms import fields 5 from django.core.exceptions import ValidationError 6 7 8 # 自定义验证规则 9 def mobile_validate(value): 10 mobile_re = re.compile(r‘^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$‘) 11 if not mobile_re.match(value): 12 raise ValidationError(‘手机号码格式错误‘) 13 14 15 class PublishForm(Form): 16 17 18 title = fields.CharField(max_length=20, 19 min_length=5, 20 error_messages={‘required‘: ‘标题不能为空‘, 21 ‘min_length‘: ‘标题最少为5个字符‘, 22 ‘max_length‘: ‘标题最多为20个字符‘}, 23 widget=widgets.TextInput(attrs={‘class‘: "form-control", 24 ‘placeholder‘: ‘标题5-20个字符‘})) 25 26 27 # 使用自定义验证规则 28 phone = fields.CharField(validators=[mobile_validate, ], 29 error_messages={‘required‘: ‘手机不能为空‘}, 30 widget=widgets.TextInput(attrs={‘class‘: "form-control", 31 ‘placeholder‘: u‘手机号码‘})) 32 33 email = fields.EmailField(required=False, 34 error_messages={‘required‘: u‘邮箱不能为空‘,‘invalid‘: u‘邮箱格式错误‘}, 35 widget=widgets.TextInput(attrs={‘class‘: "form-control", ‘placeholder‘: u‘邮箱‘}))
方法三:自定义方法
1 from django import forms 2 from django.forms import fields 3 from django.forms import widgets 4 from django.core.exceptions import ValidationError 5 from django.core.validators import RegexValidator 6 7 class FInfo(forms.Form): 8 username = fields.CharField(max_length=5, 9 validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid extension.‘, ‘invalid‘)], ) 10 email = fields.EmailField() 11 12 def clean_username(self): 13 """ 14 Form中字段中定义的格式匹配完之后,执行此方法进行验证 15 :return: 16 """ 17 value = self.cleaned_data[‘username‘] 18 if "666" in value: 19 raise ValidationError(‘666已经被玩烂了...‘, ‘invalid‘) 20 return value
方式四:同时生成多个标签进行验证
1 from django.forms import Form 2 from django.forms import widgets 3 from django.forms import fields 4 5 from django.core.validators import RegexValidator 6 7 8 ############## 自定义字段 ############## 9 class PhoneField(fields.MultiValueField): 10 def __init__(self, *args, **kwargs): 11 # Define one message for all fields. 12 error_messages = { 13 ‘incomplete‘: ‘Enter a country calling code and a phone number.‘, 14 } 15 # Or define a different message for each field. 16 f = ( 17 fields.CharField( 18 error_messages={‘incomplete‘: ‘Enter a country calling code.‘}, 19 validators=[ 20 RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid country calling code.‘), 21 ], 22 ), 23 fields.CharField( 24 error_messages={‘incomplete‘: ‘Enter a phone number.‘}, 25 validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid phone number.‘)], 26 ), 27 fields.CharField( 28 validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid extension.‘)], 29 required=False, 30 ), 31 ) 32 super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args, 33 **kwargs) 34 35 def compress(self, data_list): 36 """ 37 当用户验证都通过后,该值返回给用户 38 :param data_list: 39 :return: 40 """ 41 return data_list 42 43 ############## 自定义插件 ############## 44 class SplitPhoneWidget(widgets.MultiWidget): 45 def __init__(self): 46 ws = ( 47 widgets.TextInput(), 48 widgets.TextInput(), 49 widgets.TextInput(), 50 ) 51 super(SplitPhoneWidget, self).__init__(ws) 52 53 def decompress(self, value): 54 """ 55 处理初始值,当初始值initial不是列表时,调用该方法 56 :param value: 57 :return: 58 """ 59 if value: 60 return value.split(‘,‘) 61 return [None, None, None]
五、初始化数据
在Web应用程序中开发编写功能时,时常用到获取数据库中的数据并将值初始化在HTML中的标签上。
1、Form
1 from django.forms import Form 2 from django.forms import widgets 3 from django.forms import fields 4 from django.core.validators import RegexValidator 5 6 7 class MyForm(Form): 8 user = fields.CharField() 9 10 city = fields.ChoiceField( 11 choices=((1, ‘上海‘), (2, ‘北京‘),), 12 widget=widgets.Select 13 )
2、Views
1 from django.shortcuts import render, redirect 2 from .forms import MyForm 3 4 5 def index(request): 6 if request.method == "GET": 7 values = {‘user‘: ‘root‘, ‘city‘: 2} 8 obj = MyForm(values) 9 10 return render(request, ‘index.html‘, {‘form‘: obj}) 11 elif request.method == "POST": 12 return redirect(‘http://www.google.com‘) 13 else: 14 return redirect(‘http://www.google.com‘)
3、HTML
1 <form method="POST" enctype="multipart/form-data"> 2 {% csrf_token %} 3 <p>{{ form.user }} {{ form.user.errors }}</p> 4 <p>{{ form.city }} {{ form.city.errors }}</p> 5 6 <input type="submit"/> 7 </form>
时间: 2024-11-10 14:16:14